1. Field of the Invention.
Management of forested property often requires the removal of windfall logs, stumps and other debris without environmentally harming or disturbing seedling trees, young trees and undergrowth. Likewise, management of commercial orchard property often requires interplanting of young trees among old trees, and eventual removal of the old trees without disturbing the younger trees. Hiring of the customary heavy equipment and a crew is expensive, and is usually damaging to the environment.
As a consequence, I have invented an apparatus which attaches to the three-point hitch of a tractor, such as an orchard tractor, and which can be operated solely by the tractor driver, to lift one end of the object to be moved, and then to utilize a chain secured near the two tow points of the hitch and attached to the pickup tongs, to enable the tractor operator to skid the load to another location without imposing any additional load on the pickup tongs.
2. Description of Related Art.
Typically, in orchard clearance and forest maintenance, one or more people will wrap a cable or chain around the object to be moved, and will attach the cable or chain to a tow point on a truck or tractor. This is not only expensive in terms of labor costs, but it can get quite dangerous at times. Machinery for picking up and carrying or skidding logs or trees is generally large, specialized, expensive, and often inappropriate, considering the surroundings in which the work is to be done.
U.S. Pat. No. 2,893,778 to Eckstein discloses an automatic tongs for mounting on a shovel or boom. The device incorporates a pair of chains which are not used for hauling, but only for the purpose of opening the tongs. The pickup device takes the skidding load. In U.S. Pat. No. 3,782,567 to Likas et al., chains are used to enclose various sizes of load, but only to secure the load to the vehicle. The grapple takes the towing load. That is also the case, but without the chains, in the devices in U.S. Pat. Nos. 3,513,998 to Stone, 4,379,674 to Meisel, Jr. et al. and 4,645,410 to Royer. U.S. Pat. No. 3,972,431 to Fischer discloses a log grapple unit which also has a separate winch. The precise use of the winch is not disclosed, except for the following statement: "The winch unit 28 includes a line or cable 30 which is trained over a portion of the arch structure 26 for engaging a load to be towed by the vehicle." The cable appears in no way to be attached to the pickup device and presumably would have to be attached to the load by hand. U.S. Pat. No. 3,034,821 to Hackett discloses a device for picking up the entire load, not for skidding the load. U.S. Pat. Nos. 4,005,894 to Tucek, 4,023,848 to Bennett, 4,260,323 to Muntjanoff and U.S.S.R. Patent SU 103392 A to Forest Power Mechanical Institute simply disclose various designs of grapple heads, and do not disclose means for moving the load. The U.S.S.R. patent discloses a grapple head or tongs which is closer to the grapple part of my invention than any other, but which differs in vital respects. Examination of element 5 of the Soviet patent seems to show that it is not pivoted at its center, but rather is affixed to the lower end of piston rod 4. In contrast, the corresponding element of my invention, lower crosslink 46 is pivotally attached to the lower end of piston rod 40. In addition, the thrust of the Soviet patent is the ability of the tongs to be rotated by pressurizing a cylinder. In my invention, the grapple adapts to the orientation of the load whereas, in the Soviet patent, the grapple must be positioned by the operator.